Undulating diaphragm pumps are known, e.g. from document FR 2 744 769, in which the diaphragm is mounted to undulate between two end plates under drive from at least one linear electromagnetic actuator in order to transfer a fluid from an inlet of the pump to an outlet of the pump between the diaphragm and the end plates.
The diaphragm is fastened to a rigid diaphragm support. The movable portion of the actuator is generally coupled directly to the diaphragm support and causes the outer edge of the diaphragm to oscillate transversely, thereby giving rise to undulations in the diaphragm perpendicularly to its plane, which undulations have the effect of propelling the fluid from the inlet towards the outlet of the pump.
Advantageously, the actuator(s) is/are selected to be of the movable magnet type or indeed of the reluctance type. Nevertheless, the masses set into motion by an actuator of that type are relatively large since they comprise, for example: the magnets, the magnet supports, the parts connecting to the diaphragm support, and the suspension springs. In such a pump, the mass of the movable portions of the actuator not only affects coupling between the undulating diaphragm and the fluid, the effectiveness of diaphragm motion, and the efficiency of the pump head, but also limits the potential operating frequency of the actuator, and leads to noise and vibration that can be troublesome.
Associating a suspension spring for the movable mass does not solve those operating problems.